Differential



H. c STRATF'QRD .DIFFERENIIAL Filed July 30 1924 -/NVENTOR f/uao C, STRATFORD BY fi l/W v ATTORNEYS Patented Sept. 1, 1925.

awn c. sfmerronii, or TEWARii BRITiVSHICOLuMi siA, CANADA. I

' extrem sm; I L

1 .1) p iieatioa filed 1111 30, 1934. Serial 110,729,124.

To all 'wk om'it may concern":

- Be it known that I, HUGO C. STRATFORD, a s-ubje'ctof' the King of Great Britain, and a resident ofthe "town of Stewart, in 'the'Prov in'ce f'Briti's'h"Columbia, Canada, have invented certain new and useful Improve ments in Differentials,'o-f'which the following is'a s ecification;

"My invention relates to improvements'in difierentials'for use on automobiles and the like, the objects of' which are to provide means whereby afposit'ive andjindependent drive is communicated toeach road wheel from th drive ring sothatin the event of traction being lost to one" roadwheel through and or other" slipperyffootingtrac tion may be obtainedfby the other; a further object is'to' provideineans whereby the pawls effecting rotation of'the shafts in one direction shall b e resiliently but firmly held inplace in the ratchet wheels and the corresponding pawls for effecting rotation in the opposite direction shall be lifted out of engagement of the ratchet wheels.

The invention consists of a pair of ratchet Wheels each mounted on a shaft and enclosed within a casing to which the drive ring is fitted and carrying a plurality of pawls by which a drive is established between the drive ring and the shafts, as will be more fully described in the following specification in which Fig. 1 is a sectional view taken on the line 1-1 of Figure 2.

Fig. 2 is a sectional view taken on the line 2-2 of Figure 1 with the crown gear omitted.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numerals 1 and 2 indicate a pair of shafts in axial alignment with each other and each having a ratchet wheel 3 keyed upon its inner end. the wheels are provided with a circular boss 4 which is journalled in the casing 6 the periphery of the ratchet wheels is provided with a'plurality of transverse ratchet slots 5.

The numeral 6 indicates a casing which is formed of two annular flanges 7 having central bores 8 in which the bosses 1 of the ratchet wheels 3 are journalled and a pluralitv of inturned lugs or spacers 9 through which bolts 10 are driven to hold the Casin t3 ogether.

The numeral '11 indicates a driverring which is transversely slotted as at 12, the purpose of: which will hereinafter appear. One edge of the ring being inwardly flanged as at 13 toengage-"the' outer face arose of the flanges 7' and" the other edge being outwardlyfla'nged as at 14tofformfa'z'seating for the crown gear 15 'and to receive an annular coverring' 16 by which theio'uterface of thcoth'erifiaxnge' 7 isj engaged; "Carried in 'opposing 'recessesz17' on the innerfaces of the flanges 1'7 are a' plurality of pairs of pins 18 upon each of which pairs of pawls 19 andf20 are mounted, thepawl'sl'9 s'eparately engaging "ea-ch ratchet "wheel '3 to drive it in a forward direction. the pawls 20 separately engagingfeach' ratchetuwheel to drive'it'dn "a rearward"direction; The

pawls19 and '20 are each "provided with an upstanding lug: '21 which is recessed from the {rear of its fulcrum as at 22 to form a housing for the end of a coil spring 23 which extends between opposing pawls 19 and 20 so that each spring exerts a resilient pressure on one pawl designed to actuate in a forward direction and one to actuate in a rearward direction. The lugs 21 project into the slots 12 of the drive ring 11 so that as the crown gear 15 and the ring 11 are turned in a forward or clockwise direction the side of each slot engages the lug 21 of all the pawls 20 raising them from contact with the ratchet wheel and simultaneously imparting a resilient pressure through the springs 23 to depress the pawls 19 into the slot-s 5 of the ratchet wheels 3. The drive from the crown ring is transmitted first to the lugs of one set of pawls which are carried to lift out of engagement until the free end of the pawls encounter the spacer 9, the ring 11 being then in positive engagement with the pawl 20 transmits its power therethrough to the pins 18 and thence to the casing and thence in a corresponding manner through the pins of the pawls 19 to the pawls which engage the ratchet wheels 3.

On the rotation of the crown gear in an anti-clockwise direction the pawls 19 are raised and the drive is communicated through the pawls 20 to the ratchet wheels 3. vWhen driving around a curve the drive is communicated positively to the inner wheel while the pawls controlling the outer wheel are p m tte t ri e and fa l as the outer wheel and its shaft overrun the incasing and all the'pawls will be reversed-so as to prevent the free rotation of the ratchet wheels, thus taking up the p-osite direction.

It will thus be seen that I have invented a differential through which a positive drive is automatically transmitted to either shaft or wheel which is capable-of giving traction to the vehicle to which it is fitted.

What I claim as my invention is:

1. A dilierential gear assembly com-prising a pair of aligned driven members, a pair of spaced discs rotatable with respect to said driven members and receiving the latter therethrough, each disc being provided at theinner side with hollow spacing sleeves having-their free ends abutting the corre sponding ends ofthe opposing sleeves cardrive in the opried by the otherv'disc, there being openings formed in said discs in line with said sleeves,

' securing'bolts'passing through said aligned sleeves and openings to secure the discs together in spaced relation, a drive ring secured to rotate on theuperipheral surfaces of said discs and means acting in response to turning movement of said drive ring to tween and terminally supported by cause the driven members to move with and in the same direction as said ring.

2. A differential gear assembly comprising a pair of aligned driven members, ratchetwheels fixed to the adjoining ends of said members, a pair of spaced discs rotatably mounted at opposite sides of said ratchet wheels and receiving the driven members therethrough, a drive ring turnably mounted on the'peripheral surfaces of said discs and-provided with a series of circumferentially spaced slots, a plurality of pivot pins arranged in pairs extending bed sai discs, a pair of forward'driving pawls pivotally supported by one pin of each pair, a pair of reverse driving pawlspivotally supported by the remaining pin of each pair, opposing lugs carried by the forward and reverse driving pawls of each pair and projecting into one of the slots ofthe drive ring, and a coil spring confined between the lugs of each opposing pair and accessible through the slot receiving said lu 's.

' 3. An assembly as recited in c aim 2 in which the ratchet wheels and the engaging pawls are of substantial and equal width.

Dated at Stewart, B. (1., Canada, this 3rd day of July A. D. 1924.

HUGO C. STBATFORD. 

